Bell & Gossett DN0141D Domestic Pump 2′ NPSH Horizontal Pumps Series DB-F - Manual (Page 6)

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6. Remove discharge connection and suction connection.
Unbolt motor and or pump from base. Place assembly on
workbench.
7. Remove suction housing and then axial flow impeller,
shaft, and straightening vanes in the following manner:
Remove axial flow impeller set screws. Remove the axial
flow impeller, remove the straightening vanes, and
unscrew the shaft extension.
8. Remove cap screws holding pump volute and motor
bracket together. Remove volute by lifting straight away
from motor and bracket assembly.
9. Remove first centrifugal impeller by inserting two pry bars
between motor bracket and impeller on opposite sides of
impeller, being careful to pry equally, and ONLY WHERE
THE SHROUD OR THE IMPELLER IS SUPPORTED BY A
VANE. Lift off the diaphragm plate and wearing rings as an
assembly. Remove second centrifugal impeller, using a
puller. The machined groove on the impeller hub is for this
purpose.
10. To install new seal proceed as follows:
(1) Thoroughly clean recess in head. Moisten or soap the
“rubber” portion of seal. Press rubber and ceramic into
recess firmly by hand making certain both parts bottom
evenly. If seat cannot be bottomed with fingers place
the cardboard shipping disc on seat and force into
place with flat tool. Wipe clean with soft clean cloth to
remove dirt or excess soap.
(2) Carefully place head into position on motor shaft with-
out displacing ceramic seat, and secure bracket to
motor with cap screws.
(3) Place motor vertically with pump end up. Do not
attempt reassembly of pump with the shaft horizontal.
(4) The “carbon” of the rotating part of the seal should not
be loose. If it is, hold in place with grease. Using a
clean, lint-free cloth, wipe mating surfaces, perfectly
clean. Soap the shaft and push seal onto shaft so that
it touches the carbide seat.
(5) Replace seal collar as close as possible to original
position, and tighten the set screw.
11. Replace second impeller on shaft, being careful to bottom
it on shaft shoulder. Replace diaphragm plate with its
wearing rings, and replace first impeller. Reassemble
pump volute to bracket.
12. Reassemble propeller. Tighten thoroughly.
13. Reassemble straightening vanes, being careful to locate
properly on pin. Reassemble axial flow impeller and
tighten the set screws holding it to the propeller stem.
Reassemble suction housing using new gasket.
14. Reposition the pump in place, and bolt down. Reconnect
discharge and suction.
15. Reconnect air relief tubing and motor wiring.
NOTE: See page 4 for additional DB-F instructions
(Coupler Alignment).
16. Close drain and slowly open inlet gate valves.
17. Three phase motors should be started momentarily to
check rotation. If pump runs backward, interchange any
two motor leads. (Any electrical service should be per-
formed by a qualified electrician).
18. Observe operation thru several cycles.
PUMP SERVICE INSTRUCTIONS FOR SERIES DB AND DB-F PUMP ENDS cont.’d
CAUTION: DO NOT RUN DRY.
SEAL DAMAGE MAY OCCUR.
Inspect pump seal regularly for leaks. Replace as required.
Failure to follow these instructions could result in injury or
property damage.
WARNING: EXPLOSIBLE
Do not pressurize receiver. Do not plug overflow. Pipe
vent opening to atmosphere. Do not restrict. Open valves
slowly. Failure to follow these instructions could result in
serious injury or death.
CAUTION: DO NOT REVERSE
Reverse operation can cause extensive damage to
pumps. Jog the motor to test for direction of rotation. Failure
to follow these instructions could result in serious injury or
property damage.
SEAL COLLAR 2ND STAGE VOLUTE
MECHANICAL
SEAL COLLAR
MECHANICAL SEAL 2ND STAGE IMPELLER
DIAPHRAM
W/ WEAR RING
PIN
SHAFT EXTENSION
WASHER
SET SCREW
FIRST STAGE VOLUTE
FIRST STAGE
IMPELLER
SUCTION
HOUSING
PIN
PROPELLER
DIFFUSER
1 5
1 6
2DPB03
SERIES DB CROSS SECTION
1. Close pump isolation valve or system return line valve.
Operate pump momentarily to discharge as much water as
possible. Close pump discharge valve.
2. Shut-off and lock out power.
3. Make sure unit is cool enough that pump can be handled
safely. Open drain to remove remaining liquid.
PUMP SERVICE INSTRUCTIONS FOR SERIES HB17 AND HB35 PUMPS
CAUTION: HOT SURFACES
Surfaces may be hot when system is in operation. Do
not tough exposed components, let unit cool before servic-
ing. Failure to follow these instructions could result in seri-
ous injury or death.
WARNING: HIGH VOLTAGE
Disconnect and lock out power before connecting or
servicing unit. Failure to follow these instructions could
result in serious injury or death.